<%
            String req = request.getParameter("req");
            try {
                int zipcode = Integer.parseInt(req);
                if (req.length() != 4) {
                    out.println("<img id=\"valid_zipcode\" alt=\":(\" src=\"../pictures/invalid.jpg\"/>");
                    session.setAttribute("VALID_ZIPCODE", "FALSE");
                } else {
                    out.println("<img id=\"valid_zipcode\" alt=\":)\" src=\"../pictures/valid.jpg\"/>");
                    session.setAttribute("VALID_ZIPCODE", "TRUE");
                }
            } catch (Exception ex) {
                out.println("<img id=\"valid_zipcode\" alt=\":(\" src=\"../pictures/invalid.jpg\"/>");
                session.setAttribute("VALID_ZIPCODE", "FALSE");
            }

%>
